Which of the following best describes a comet?
- A. A small planet orbiting the Sun between Mars and Jupiter.
- B. A chunk composed primarily of metal that enters Earth's atmosphere.
- C. A chunk composed primarily of rock, ice, and dust orbiting the Sun in an elliptical path.
- D. A dark region that appears periodically on the surface of the Sun.
Correct Answer & Rationale
Correct Answer: C
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Other Related Questions
Earth's diameter is approximately 12,700 kilometers. Which of the following layers is located approximately 6,000 kilometers beneath Earth's surface and is composed primarily of iron and nickel?
- A. The core
- B. The crust
- C. The lithosphere
- D. The mantle
Correct Answer & Rationale
Correct Answer: A
The core, located about 6,000 kilometers beneath Earth's surface, is primarily composed of iron and nickel, making it the densest layer of the planet. The crust, option B, is the outermost layer and is much shallower, averaging only about 30 kilometers thick. Option C, the lithosphere, includes the crust and the uppermost part of the mantle, but it does not reach anywhere near 6,000 kilometers deep. The mantle, option D, lies between the crust and the core, extending to about 2,900 kilometers down, but it is primarily composed of silicate minerals, not iron and nickel.
The core, located about 6,000 kilometers beneath Earth's surface, is primarily composed of iron and nickel, making it the densest layer of the planet. The crust, option B, is the outermost layer and is much shallower, averaging only about 30 kilometers thick. Option C, the lithosphere, includes the crust and the uppermost part of the mantle, but it does not reach anywhere near 6,000 kilometers deep. The mantle, option D, lies between the crust and the core, extending to about 2,900 kilometers down, but it is primarily composed of silicate minerals, not iron and nickel.
The rotation of Earth around its axis is responsible for which of the following?
- A. The force of gravity
- B. The day and night cycle
- C. The temperature differences between seasons
- D. The movement of continents relative to one another
Correct Answer & Rationale
Correct Answer: B
The rotation of Earth around its axis creates the day and night cycle, as different parts of the planet face the Sun and then move into its shadow. This explains why we experience daytime and nighttime in a 24-hour period. Option A is incorrect; gravity is primarily caused by Earth's mass, not its rotation. Option C is also wrong; temperature differences between seasons are due to Earth's tilt and its orbit around the Sun, not its rotation. Lastly, option D misrepresents the concept; the movement of continents is influenced by tectonic activity, not the rotation of Earth.
The rotation of Earth around its axis creates the day and night cycle, as different parts of the planet face the Sun and then move into its shadow. This explains why we experience daytime and nighttime in a 24-hour period. Option A is incorrect; gravity is primarily caused by Earth's mass, not its rotation. Option C is also wrong; temperature differences between seasons are due to Earth's tilt and its orbit around the Sun, not its rotation. Lastly, option D misrepresents the concept; the movement of continents is influenced by tectonic activity, not the rotation of Earth.
Which of the following plant structures are specialized for the absorption of water and nutrients from the environment?
- A. Roots
- B. Leaves
- C. Flowers
- D. Stems
Correct Answer & Rationale
Correct Answer: A
Roots are specialized structures designed for the absorption of water and nutrients from the soil, featuring a large surface area and root hairs that enhance their efficiency. Leaves primarily function in photosynthesis and gas exchange, not nutrient absorption. Flowers are reproductive structures that facilitate pollination and seed production, playing no direct role in nutrient uptake. Stems support the plant and transport water and nutrients between roots and leaves, but they do not absorb them. Thus, roots are uniquely equipped for this essential task.
Roots are specialized structures designed for the absorption of water and nutrients from the soil, featuring a large surface area and root hairs that enhance their efficiency. Leaves primarily function in photosynthesis and gas exchange, not nutrient absorption. Flowers are reproductive structures that facilitate pollination and seed production, playing no direct role in nutrient uptake. Stems support the plant and transport water and nutrients between roots and leaves, but they do not absorb them. Thus, roots are uniquely equipped for this essential task.
Which of the following is a statement that proposes a possible explanation for a phenomenon and can be tested through experimentation?
- A. An observation
- B. A variable
- C. An experiment
- D. A hypothesis
Correct Answer & Rationale
Correct Answer: D
A hypothesis is a statement that proposes a possible explanation for a phenomenon and can be tested through experimentation. It serves as a foundation for scientific inquiry. Option A, an observation, refers to data gathered through the senses and does not propose an explanation. Option B, a variable, is a factor that can change in an experiment but does not itself explain phenomena. Option C, an experiment, is a method used to test a hypothesis but is not a statement proposing an explanation. Thus, only a hypothesis encapsulates a testable explanation.
A hypothesis is a statement that proposes a possible explanation for a phenomenon and can be tested through experimentation. It serves as a foundation for scientific inquiry. Option A, an observation, refers to data gathered through the senses and does not propose an explanation. Option B, a variable, is a factor that can change in an experiment but does not itself explain phenomena. Option C, an experiment, is a method used to test a hypothesis but is not a statement proposing an explanation. Thus, only a hypothesis encapsulates a testable explanation.